Craig Thomas obituary

Although not technically minded, Craig Thomas was able to steep his books in intricate detail, the result of meticulous research

Craig Thomas, who has died from pneumonia aged 68, was at the forefront of the spy/adventure genre known as the techno-thriller, novels in which technology – usually cutting-edge military hardware extrapolated from current technological advances – is central to the plot. Thomas's 1977 novel Firefox featured the fictional MiG-31, an aircraft so advanced that it would immediately give the Russians the upper hand.

At the time, the Russians had the MiG-25 Foxbat, the fastest reconnaissance bomber and interceptor in the air, with a top speed of Mach 2.8. Thomas's Firefox could achieve speeds of Mach 5, had stealth technology which made it invisible to radar and a guided missile system controlled by the pilot by thought alone. Realising the implications to security in the west, his British spymaster Kenneth Aubrey suggests an audacious plan to steal one of the two prototype aircraft.

Firefox was filmed in 1982, with Clint Eastwood directing and starring as Major Mitchell Gant, an American fighter pilot and Vietnam PoW traumatised by seeing a young girl incinerated by napalm.

The book was a bestseller, with its publishers, Sphere, gambling on recent real-life events – the defection in 1976 of the Soviet pilot Viktor Belenko to the US via Japan with a Foxbat – to risk a 250,000-copy paperback edition. The book went through 33 printings over the next 17 years, helping to propel Thomas's sales to more than 20m by the time Gant made his fourth and final appearance in A Different War (1997).

Although not technically minded, Thomas was able to steep his books in intricate detail, the result of meticulous research. The background material for Firefox was provided by friends formerly with the RAF, and the Russian setting was derived from guidebooks and photographic books. He could not afford to visit Moscow – a situation soon solved by the book's tremendous success, which allowed him to become a full-time writer. By then, he did not think it prudent to take a holiday in Russia, saying: "I don't think I'm their favourite novelist."

Thomas was born in Cardiff, the son of JBG Thomas, a rugby journalist on the Western Mail, and his wife, Gwen. Educated at Cardiff high school and University College, Cardiff, he would later say that his five years at university completing an MA on Thomas Hardy sealed his fate: "It was a life connection with literature, with the magic of words."

He began teaching English at schools in the West Midlands and, after a day of Shakespeare, Dickens and Keats, would read thrillers – John le Carré, Frederick Forsyth, Len Deighton, Alistair MacLean, Jack Higgins and Adam Hall – for entertainment. When he joined the ranks of thriller writers himself, he read the classics for pleasure.

Thomas had begun writing as a boy, firing off short stories to magazines without success. As a teacher, he tried writing radio scripts for the BBC, having discovered that he did not need to write the whole thing, just a cast list, an outline of the plot and six sample pages of dialogue.

He continued to write these "in a rather amateurish and occasional way" for five or six years until one of the editors who read his outlines offered some advice, saying that while Thomas could write, radio drama was not his medium and he should try a novel instead. "Perhaps he hoped never to hear from me again," said Thomas, "but he provided what was the single most important piece of practical advice I have ever received. It changed my life."

At the time, Thomas was toying with an idea for a thriller as his next submission to the BBC. Instead, he spent 18 months turning it into a novel. Even he could see the end results would require a lot of editing and rewriting, and he put it aside. But the experience did not go to waste. His next attempt, Rat Trap (1976), about the hijack of a British Airways 707 by an American and five accomplices who want to trade passengers for an imprisoned Arab terrorist, took three months to write and was sold to Michael Joseph (now part of Penguin). He immediately followed it with Firefox, which took only four and a half months to complete.

Quitting his position as senior English teacher at Shire Oak school, Walsall, Thomas continued to write tales of espionage. Wolfsbane (1978) established the history of two characters already seen in his work: Aubrey (from Firefox) and Hilary Latymer (from Rat Trap). In 1944, they are both working for the Special Operations Executive and, by the time of the novel's 1963 setting, are with the SIS (MI6), of which Aubrey would subsequently become head. Aubrey was a key link in all 16 of Thomas's espionage novels, often at the forefront – in Snow Falcon (1979), The Bear's Tears (1985, published as Lion's Run in the US) and All the Grey Cats (1988, Wildcat in the US) – or playing a background role, usually to Gant or the agent Patrick Hyde.

Gant was reintroduced in Firefox Down, which begins seconds after the events of Firefox, and Winter Hawk (1987), about a Russian space weapons platform. His final appearance saw him investigating the destruction of a prototype airliner. The Australian ex-SAS officer Hyde took the lead in seven of Thomas's novels: Sea Leopard (1981), Jade Tiger (1982), The Bear's Tears, The Last Raven (1990), A Hooded Crow (1992), Playing With Cobras (1993) and Slipping into Shadow (1998).

Other characters – who included Aubrey's assistant Peter Shelley, Gant's Russian nemesis Dmitri Priabin, and the KGB agent Alexei Vorontsyev, who had leading roles in Snow Falcon and A Wild Justice (1995) – were woven into these interconnected novels, creating a much larger tapestry.

Thomas wrote two further, unrelated novels, as David Grant: Moscow 5000 (1979), about a terrorist plot to bomb the Moscow Olympics; and Emerald Decision (1980), in which a man (in the 1940s) and his son (in the 1980s) seek out the truth about Nazi involvement in Ireland.

Thomas's hobbies included watching cricket, gardening and listening to music. His fascination with philosophy and political theory led him to write There to Here: Ideas of Political Society (1991) and, completed shortly before his death, a study of Friedrich Nietzsche.

In 1967 Thomas married Jill White, who also acted as his editor, secretary and bookkeeper. They lived for many years in Staffordshire but had recently moved to Somerset. She survives him.

• David Craig Owen Thomas, author, born 24 November 1942; died 4 April 2011